I am picturing here a system wherein if you ask a question without specifying some key information that is almost certainly required to answer the question correctly, a pop-up (just like the "please consider adding a comment if you think this post can be improved"; not a pop-up pop-up) will alert you to this fact and perhaps even suggest appropriate tags. Maybe this is better explained by example:

Stack Overflow example

A "How do I make a regex to find this ..." question that doesn't mention the environment in which it will be used (Perl, POSIX, Java, .Net, etc. all have different "regex flavors" and can behave very differently). The system will detect the use of a keyword or tag ("regex") but the absence of a handful of critically important keywords ("Perl", "POSIX", "Java"...) anywhere in the title, question, or tags and will alert the user to this fact. It shouldn't by any means block the user from submitting the question without this information; it should just be a gentle reminder.

Super User example

"How do I format a disk" but no mention of which OS they're using. "Format" is detected, but not any of "Linux", "Windows", "OS X", etc. Same principle.

Architecturally I'd imagine this being just a bit more meta data attached to tags, called "crucial information" or something.

This sounds like a whole lot of work to implement something which is going to have a lot of AI holes in it, when the best option is still going to be a user commenting on the question and saying "you need to include X, Y, and Z."